Relay



July 3, 1962 J. 5. JORDAN 3,042,775

RELAY Filed Sept. 9, 1959 2 Sheets-Sheet 1 July 3, 1962 RELAY FiledSept. 9, 1959 2 Sheets-Sheet 2 jig/L Z Z mmvaon 5 X 40 "YE/1M,

J. s. JORDAN 3,042,775

3,042,775 RELAY John S. Jordan, Galion, Ohio, assignor to North ElectricCompany, Gallon, Ohio, a corporation of Ohio Filed Sept. 9, 1959, Ser.No. 838,959 7 Claims. (Cl. 200-104) The present invention relates torelays, and particularly, to improvements in the construction of relaysof the character disclosed in, and especially adapted to serve the usesand satisfy the conditions described in, the co-pending application ofLeonard J. Greshel, Serial No. 839,009, filed September 9, 1959, whichapplication 18 assigned to the assignee of this application.

The object of the invention is to provide constructional improvements inrelay structures of the type comprising 3,042,775 Patented July 3, 1962ice 2 Vernier-like adjustment of the armature means even by a relativelycoarsely threaded screw.

It is a particular object of the invention to provide the aforesaidadjusting means for the armature return spring and to embody theadjustment in a compact economical structure wherein the screw isthreaded through an angularly disposed portion of one of the polepieces.

a stacked arrangement of a single coil having an axial I core, aterminal header disposed in spaced parallel relation to the core and anarmature sandwiched between the header and the core; the structureincludes pole pieces fixed to the opposite ends of'the core andextending into the space between the header and the core, one extendingbetween the armature and the core and the other between the armature andthe header, a plurality of movable contacts mounted directly on theheader at the side thereof adjacent the armature, and a plurality ofactuators carried by the armature and extending respectively to themovable contacts.

It is specifically one object of the present invention to provide arelay structure as above describedwherein the actuators .are caused tomove in an arc the mid-point ment of the pole pieces and the armaturefor causing the armature to move in an are at the mid-point of which thearmature is parallel to the header.

More particularly, it is an object of the invention to provide animproved relay structure of the character described wherein the polepieces are inclined relative to the axis of the coil core at aninclination equal approximately-to one-half the arcuatemovement of thearmature about its pivot axis whereby the armature at the mid-point ofits movement is parallel to the contact and terminal header. I p

An additional object of the invention is the embodiment in relaystructures of the character described of improved armature pivot meansfor enhancing armature balance, the said means being characterized inthat the pivot axis is offset from the transverse axis of the armaturein the direction or directions of the instrumentalities carried by thearmature for purposesof counter-balanc ing such instrumentalities, e.g.,the contact actuators and the armature return spring. p p

A further object of the invention is the provision in relay structuresof improved means for adjusting .the characteristics of the armature,the said improved means comprising a screw engageable with the armaturemeans at an angle significantly less than a right angle relative to theplane of said armature means for accommodating A still further object ofthe invention is the provision of improved means'for constituting theaforesaid coil core, pole pieces and header a compact rigid frame forthe relay and for facilitating access to the relay adjusting means; theframe according to the present invention comprising a coil core, polepieces fixed to the opposite ends of the core, a header disposed inspaced parallel relation to the core, and a pair of U-shaped straps orsupports secured at their bights to the opposite ends of the header andat their legs to the respective pole pieces thereby to constitute thewhole a rigid relay frame, the U-shape of the straps facilitating accessto the space between the header and the core. I Yet another object ofthe invention is the provision of a relay structure of the characterdescribed including improved contact actuators'and an'irnproved mountingfor said actuators on the relay armature.

In addition to the foregoing, it is an object of this invention toincorporate at least some of the aforesaid improvements not only inrelays having a normally released spring biased armature, but inlatching relays as well.

Other objects and advantages of the invention will become apparent inthe following detailed description.

Now, in order to acquaint those skilled in the art with the manner ofmaking .and using my improved relay structure, I shall describe, inconnection with the accompanying drawings, preferred embodiments of thestructure and preferred manners of making and using the same.

In the drawings, wherein like reference numerals indi-' cate like parts:

FIGURE 1 is a perspective view of a first embodiment of the relaystructure of the invention, the view showing the relay with its outerhermetic sealing can removed;

FIGURE 2 is a fragmentary vertical section taken substantially on line2-2 of FIGURE 1;

FIGURE 3 is'a fragmentary longitudinal section showing, on an enlargedscale, one pole piece, the armature, theactuators, the armature returnspring and the spring adjusting screw of my improved relay structure;

FIGURE 4 is a schematic elevational representation of the coil, polepieces, armature, one actuator pair and one contact set of the relaystructure of the invention, the view illustrating these components intheir unoperated positions; FIGURE 5 is a view similar to FIGURE 4, butshowing the armature, the actuator pair and the contact set in operatedposition} FIGURE 6 is a view similar to FIGURES 4 and 5, but showing themovable components at the mid-point of their travel; 7

FIGURE 7 is a detail view of the improved armature mounting providedaccording to the invention; and

FIGURE 8 is a view similar to FIGURES 4 to 6 illustrating the latchingrelay embodiment of this invention.

Referring now to the drawings, and particularly to FIGURES 1 and 2, therelay construction to which the present invention relates comprised of astacked arrangemcnt of a coil assembly 10, a terminal header 12paralleling the axis of the coil assembly in spaced relation thereto,and an armature 14 sandwiched between the header and the coil assembly.

The coil assembly includes a rigid axial core 16, a coil 18 wound on thecore, and a coil enclosing can 20 through the ends 22 of which the coreprotrudes. The coil 18 is wound directly on the core for maximumutilization of winding space, or in other words, to maintain at aminimum the external dimensions of the coil. The components of the can20 are hermetically sealed to one another and the core 16 therebysealingly to enclose the coil 18.

To each of the protruding ends of the core 16 is fixedly secured a rigidpole piece 24 and 26, respectively. The pole pieces are preferably fixedto the ends of the core by peening protruding portions of the core intocountersunk holes in the two pole pieces, each pole piece and the corehaving smooth mating faces and the assembly being held under pressureduring peening, thereby to afford a structure that essentially is boththe physical and mag netic equivalent of a one-piece structure.Preferably, the magnet material used is a nickel-iron alloy. The polepieces 24 and 26 extend radially in the same direction from the core 16,and radially outward of the can 20 are extended toward one another inrespective planes that are parallel to and spaced from one another tosuch extent that the distance between the lower surface of the polepiece 26 and the upper surface of the pole piece 24 is equalapproximately to the thickness of the armature and residual if present.

The terminal header 12 is a rectangular planar member of a length equalsubstantially to the core 16 and of a width not significantly greaterthan the coil enclosing can 20. This member is preferably formed ofmetal having relatively low permeability, and it is rigidly joined tothe pole pieces by means having negligible permeability. According tothe present invention, the header is secured to the pole pieces 24 and26 by U-shaped supports 28 which are preferably formed of stainlesssteel, the legs of each U being secured, as by welding, to the oppositesides of the respective pole piece 24, 26 and the bight portion thereofconstituting the mounting surface for the header, to which the header isfixed as by welding, whereby the header is disposed in spaced parallelrelation to the coil assembly at the same side thereof as the ends ofthe pole pieces. To conserve space and provide a compact assembly, thepole pieces 24, 26 are of a width less than the width of the can 2t? andthe U-shaped straps or supports 28 are of a width no greater than thatof the can and the header 12-. The legs of each strap are Welded to theside surfaces of the respective pole piece and the bight of each strapis welded to the surface of the header adjacent the armature at therespective end of the header. Thus, the supports or straps 28 facilitatea compact assembly and constitute with the core, the pole pieces and theheader a rigid frame, and facilitate access tothe space between theheader and the can 20.

As thus assembled, the core 16, the pole pieces 24 and 26, the header 12and the supports 28 comprise a rigid box-like frame for the relay, whichframe has the necessary mechanical strength to endure the high shock andvibration environment to be encountered by the relay, and the strains tobe imposed thereon by virtue of the wide variation in temperature towhich the relay is to be exposed. Consequently, this rigid frame is welladapted for said axis extends in spaced parallel relation to the header12 transversely of the axis of the coil and itscore at a pointintermediate the planes of the end portions of the pole pieces 24 and26. The bearings 32 arepreferably formed by a forward and reversedrawing operation whereby each includes an inwardly extending bulbousportion having a cylindrical center or core portion.

The armature 14 comprises a substantially rectangular planar memberpivotally mounted on the bracket 30 on a transverse pivot axis disposedgenerally centrally thereof and having its longitudinal axis extendingin the same direction as the core 16 and the header 12. At the oppositesides thereof, and coincident with the said transverse pivot axis, thearmature carries a pair of balls 34 comprising the bearings thereof.Preferably, the balls are formed of stainless steel to close toleranceand are welded to the armature.

The bearing balls 34 of the armature are journalled in the cylindricalcore portions of the journal bearings 32 to have substantially acircular line of bearing contact therewith. Bearing play is held toextremely close limits of from about .00005 inch to about .00010 inch tornitigate armature vibration and maintain relay adjustments under allconditions. Also, the reverse draw of the journal bearings 32 affords acurved smooth surface to.

minimize frictional resistance to movement when the side edges of thearmature engage the armature mounting bracket.

The armature 14 is formed of metal having high permeability. Thearmature mounting bracket 30 is preferably formed of beryllium copperbecause of the formability, hardenability and non-magnetic properties ofthis metal. After formation, the bracket is age-hardened for minimumwear and maximum vibration resistance. This journal, in combination withthe'stainless steel ball bearings, affords an exceedingly accurate pivotfor the armature, and one that will have exceptionally long servicelife.

The armature thus extends generally in the same direction as the header512 and core 16 and is sandwiched between the two with its left endextending below the end portion of the pole piece 26 and its right endextending above the end portion of the pole piece 24, whereby thearmature is adapted to be attracted by the pole pieces upon energizationof the coil 18. Generally speaking, the armature is movable in apredetermined are about its pivot axis, and it is one object of thisinvention to so mount the armature that it is parallel to theheader 12when it is at the midpoint of its arcuate path of movement. To this end,the portions of the pole pieces 24, 26 opposed to the armature areinclined relative to the header at an inclination equal approximately toonehalf the arcuate movement of the armature. Specifically, the polepiece 24 is extended radially from the core 16 and outwardly of thearmature it is inclined away from i the header toward the armature atthe selected angle;

definition of a fixed pivot axis for the armature 14. The

armature is mounted on the said frame by means of a U-shaped bracket 30which is rigidly secured to the frame,

7 preferably by welding the side portions of the same to the left-handpole piece 26 at the side of the pole piece. The legs of the bracket 30extend inwardly to opposite sides of the pole piece 26, within theconfines of the boxlike frame, and at the inner ends thereof includebearing portions 32 defining a pivot axis for the armature. The

the pole piece 26 is extended radially from the core and outwardly ofthe can it is inclined away from the core and toward the armature at thesaid selected angleyand the inclined portions of the two pole pieces aredisposed in spaced parallel relation with the distance between theplanes of the adjacent surfaces of the pole pieces equal approximatelyto the thickness of the armature and the residual if present. In itsoperated position, the armature is disposed at substantially the sameinclination as the pole pieces and substantially engagesthe same.Residuals (not shown) may comprise non-magnetic plates or platings onthe opposed surfaces of the armature and/or the pole pieces, or maycomprise adjustable residual screws. To return the armature from itsoperated position, a return spring 36 is fixed to one end of thearmature, and

to limit movement of the armature away from the pole pieces under theurge of the spring a back stop 37 is provided which acts to retain thearmature in a normal position inclined oppositely from the inclinedoperated position thereof. Thus, the armature is movable in an are atthe midpoint of which the armature is parallel to the header, wherebythe relay structure affords particular advantages to be described indetail hereinafter.

With respect to the armature return spring 36 and its back stop 37, itis an object of this invention to provide improved means for effectingaccurate adjustment of the armature characteristics. Specifically, Iprovide means whereby the armature is adjusted by screws which extend atan angle significantly less than a right angle relative to the plane ofthe armature means thereby to aiford a vernier-like adjustment evenwhile employing a relatively coarsely threaded screw. To this end, thereturn spring 36 comprises a flat strip of beryllium copper or the likefixed to the upper surface of the right-hand portion of the armature andreacting against an abutment screw 38 which extends at an angle in theorder of about 45 degrees to the plane ofthe spring. To facilitatemounting'of the screw at such angle, theright-hand pole piece 24includes an angular portion intermediate the portions thereof extendingradially of the core and generally in the direction of the core, theangle of which intermediate portion is in the order of about 45 degreesrelative to the said radial portion. The screw 38, which is preferablyformed of stainless steel, is threaded directly through saidintermediate portion thereby to engage the spring at the aforesaidangle. Also, this construction leaves the end of the screw freelyaccessible between the legs of the U-shaped support 28 whereby thespring is readily adjusted to exacting specifications. In similar mannerthe back stop 37 comprises an adjustable screw extending at an. angle inthe order of about 45 degrees to the plane of the armature. In thiscase, the screw, is threaded through a nut 39 which is welded to the canadjacent the righthand end thereof whereby the screw 37 is 'engageablewith the upper surface of the right-hand end portion of the armature tolimit the return movement thereof. Again to conserve space andfacilitate the construction, the lower corner portions of the can arecomprised of portions inclined at about 45 degrees to the planes ofthesides and bottom of the can 20, whereby the nut 39 is convenientlydisposed at the appropriate angle relative to the plane of the armatureand the adjusting screw 37 is accommodated entirely within the confinesof the box-like frame defined by the can, the supports and the header(see FIGURE 2).

Secured to and projecting downwardly from the armature, i.e., toward theheader 12, are a plurality of actuators 40 which-will serve to actuatethe movable ones of contact means carried by the header. In theillustrated construction, there are four contact sets each having a pairof movable contact means. Consequently, the armature carries four pairsof actuators each comprising a stainless. steel wire having a glass bead42 at its lower end forengagement with the respective movable con tact.As will be appreciated, the armature may carry more or less actuators asmay be required for any particular contact assembly, theassemblies'contemplated,

however, requiring an even number of actuators. For any such assembly,the actuators are of even numbers to opposite sides of the armaturepivot axis and corresponding actuators to opposite sides of said axisare spaced equal distances from that axis to accommodate a balancedassembly. To accommodate the actuators at the right end ofthe armature,the end portion of the right-hand pole .piece 24 is slottedlongitudinally thereof, as is indicated at 44.

The terminal header 12 is provided with a plurality of terminalsprojecting therethrough which terminals, at the side of the header 12adjacent the armature, directly carry and/or constitute the contactmeans of the contact assembly embodied in the relay, whereby the movablecontacts are disposed to be conveniently actuated by the armature,-therelay assembly is decreased in size and no leads are required betweenthe terminals and the contacts. In FIGURES 1 and 2, I have indicated thecontact mounting terminals at 46, the stationary contacts at seals 52.

48 and the movable contacts at 50. The specific arrangement of thedisclosed assembly is described in detail in the aforesaid co-pendingapplication of Leonard J.

Greshel. For the present, suffice it to say that there are threeparallel rows of terminals 46, the center row of which carries themovable contacts .50 and the outboard rows of which carry thestationarycontacts 48, the several contacts being mounted on the terminals to theside of the header adjacent the armature.

As previously stated, the header plate 12 is preferably formed of metal.This plate is provided with holes therethrough for reception of theterminals 46, which are in the form of rigid pins extendedperpendicularly through the plate and iusulatedly sealed thereto byglass compression Each stationary contact 48 comprises a barrelshapedmember formed of precious metal and telescoped onto and soldered orotherwise secured to the respective pin 46. The movable contacts 50 areeach fabricated of a pair of generally U-shaped springs secured at theends of respective legs thereof to the opposite sides of a respectivepin 46 in the center row, whereby each contact 50 is of S-shape and hasits terminal pin disposed centrally thereof. By virtue of thisconstruction, each end of each spring 50 is disposed to be moved in thedirection of the longitudinal axis of the header and to engage arespective stationary contact 48. The S-shaped springs 50 are eachpro-stressed so that the ends thereof are normally biased towardpressure engagement with their respective stationary con-tacts 48thereby to aiford a permissive-make contact arrangement.

The movable contact springs 50 are actuated by the actuators 40, theglass beads 42 of which afford insulated Each spring 50 requires'twoactuators, and the actuators are thus provided in pairs, one pair foreach spring. The

actuators of each pair are disposed respectively adjacent the free endsof the spring to the side of the respective end facing toward therespective stationary contact 48, whereby the actuator is adapted tomove the contact 50 away from one contact 48 and to permit the contact50 to move into engagement with the other associated contact 48 uponappropriate movementof the armature 14. The actuators of each pair, dueto the disposition of the respective spring 50, define a planeperpendicular to the plane of the armature and inclined relative to theaxes of the armature, and each pair of actuators may suitably be securedto the armature as a unit at this approximate inclination in assembly ofthe armature and actuators. In particular, the armature ispreferably'provided,along its longitudinal axis with a plurality ofpairs of. holes. Each actuator of the respective pair of actuators isinserted in one hole of the respective pair and the two actuators of thepair are commonly secured to the armature by a single staking operationwhereby the material of the armature and the two actuators is commonlyupset, as indicated at 53. The actuators may be staked to the armatureboth at the upper and lower surfaces of the armature as indicated, or asingle stake may be effected at the lower surface of the armature. Afterassembly, the stainless steel wires forming the actuators may readily bebent to efiect adjustment of the contacts and the operatingcharacteristics of the relay.

In particular, the actuator wires may be so adjusted as to provideeither a makebefore-break or a break-beforemake characteristic asdesired. the respective glass beads 42 are separated from the closedcontacts in the end positions of armature movement, thereby to insure apermissive-make contact arrangement as previously described. Inparticular, each actuator wire 40 is so adjusted as to provide betweenthe glass bead and its associated movable contact, in the contact closedposition, a gap of from .002 inch to .004 inch. Each spring is thusclosed under its own tension, and the arrangement allows for somearmature bounce on operation and release and for some armature motionduring shock and vibration without affecting the closed contacts. Thismini In either case, however,

mizes contact bounce and chatter during vibration, and also minimizesvariation in contact pressure thereby to increase contact life.

Contact life is further increased by complete elimination of organicmaterials from the vicinity of the contacts. In particular, the relay isso constructed as to facilitate enclosure of the contacts in acontaminant-free atmosphere. As the first step in this direction, thecoil 18 is enclosed in its own hermetically sealed can 20. To supplycurrent to the coil, the coil ends are secured to terminal pins 54 whichextend through the inclined lower corner walls of the can 20 ininsulatedly sealed relation thereto, the pins preferably beingglass-sealed, as at 56, in the same manner as the terminals 46. Theterminal pins 54 extend from: diagonally opposite lower corner portionsof the can 28 and are connected, by means of non-contaminant leads 55,to respective adjacent ones of a pair of current supply terminals 60which are mounted in diagonally opposite corner portions of the header12;. The terminals 60 are mounted in the same manner as the pins 46, andare each preferably aligned with the pins 46' in the respective outboardrow of pins thereby to afford a compact, unitary terminal assembly forthe relay. The leads 5% may be insulated by a coating of glass, or maybe left uninsulated, so long as there is no organic or contaminantmaterial involved. As the final step, the entire relay assembly ishermetically sealed within a second can (not shown) which fits down overthe can 20, the pole pieces 24 and 26, the supports 28 and the edge ofthe header 12, and is hermetically sealed about the edge of the header.In the resultant structure, the space between the coil as sembly l andthe header 12 is closed and hermetically sealed. The only materialswithin this space are metal and glass, which are non-contaminants. Theonly relatively moving parts are stainless steel on hardened berylliumcopper and glass on the hardened alloy of the contact springs. Thus,there is nothing Within the sealed space that could contaminate thecontacts, interfere with their operation, or hasten their wear.Moreover, the armature bearings are thus also sealed within acontaminant-free atmosphere thereby to insure long service life for thebearings and the contacts.

In view of the foregoing, it is to be appreciated that the describedstructure provides a strong, rigid relay that is exceptionally compact,that facilitates manufacture of relays in small sizes and to exactingspecifications, that facilitates accurate production of small relays bymass production methods and that assures long, eificient service lifefor the relay due not only to the constructional features involved butthe enclosure of all operational components in a contaminant-freeatmosphere.

As a specific example of the physical capabilities of the relaystructure, the same has been embodied within an exterior enclosure can 1/4 inches high, 1% inches long, and /3 of an inch wide. The weight ofthe relay is only .13 pound. The relay withstands vibration in the orderof -20 gravities at 10 to 2000 cycles per second and shock in the orderof 50-75 gravities of 11 millisecond duration. It operates over atemperature range of minus 65 degrees C. to plus 125 degrees C.

The rigid frame structure provided by my U-shaped supports accommodatesthe described high resistance to shock and vibration; the screwadjustment facilitates ac curate setting of the armature and the returnforce there on and permits finite adjustment of the operate and releasecharacteristics of the relay; and the particular mounting of the contactactuators facilitates not only the construction of the relay but thesubsequent adjustment of the actuators relative to their respectivecontacts. The disposition of the pole pieces at the describedinclination imparts symmetry to the arcuate movement of the armaturerelative to the other components of the relay, and this in turn aifordsnotable advantages with respect to contact actuation.

In particular, as depicted schematically in FIGURES 8 4 to 6, thearmature 14 is movable from a normally in clined released position (FIG.4) to an equally but oppositely inclined operated position (FIG. 5),whereby the armature at the midpoint of its travel is parallel to the.

Consequently, the actuator, in moving with the armature from released tooperated position or vice versa, is moved through an arc the midpoint ofwhich is coincident with the centerline of the contact so that themaximum excursion of the'actuator away from said centerline is no morethan one-half the total are of movement of the actuator. Considering,for example, the left hand actuator illustrated in FIGURES 4 to 6, it ismoved from a position wherein its'glass head is a certain distance belowthe centerline of the contact (FIG. 4) to a position wherein the bead isan equal distance above the centerline of the contact (FIG. 5). Becauseof this, exertion of unblanced forces on the contacts is minimizedthereby to mitigate twisting or warping of the movable contact springsand exertion of forces thereon that would tend to hasten spring fatigue.In the exemplary relay above described, armature movement could suitablybe about 4, in which case the pole pieces 24 and 26 are inclined atabout 2 relative to the plane of the header and the axis of the core.With this movement of the armature, horizontal displacement of all ofactuator heads is equal, in the specific example about .015 inch.Vertical displacement of the end beads is about .028 inch, of the nextinwardly beads about .014 inch, and of the middle beads about 0.002inch. In each case, bead vertical displacement from the centerline ofthe respective contact is no more than approximately one-half the figuregiven.

In addition to the above, it is a further object of this invention toincrease the resistance of the armature to shock, vibration andacceleration. As above noted, the actuators are disposed incounterbalancing relation to one another relative to the pivot axis ofthe armature, and the movable contacts are arranged in a similarlycompensating manner. However, the actuators all project from one side ofthe armature and thereby produce an unbalanced efi'ect. To an extent,the actuators are counterbalanced by the return spring 36 which ismounted on the surface of the armature opposite that from which theactuators protrude. Further to compensate for the weight of theactuators, I offset the pivot axisof the armature laterally of thearmature in the direction of the actuators, and to compensate for thereturn spring, I offset the pivot axis longitudinally of the armature inthe direction of the return spring, whereby the pivot axis of thearmature, and thus the ball 34, is ofiset from the central transverseaxis of the armature in the manner depicted in FIGURE 7. The degree ofoffsetting the armature pivot axis and pivot ball as shown in FIGS. 3and 7 is exaggerated for purposes of illustration. In other words, Ihave located the pivot axis of the, armature to pass substantiallythrough the center of gravity of the assembly comprised of the armature,the return spring, and the actuators and their beads, thereby to providea balanced assembly. 7

In view of the foregoing, it is to be appreciated that the structuralimprovements provided according to the present invention result in acompact, rigid relay that is constructed to exacting specifications in aconvenient and facile manner, that assures long contact life andaccurate actuation of the contacts, that facilitates sealing of themovable components of the relay in a contaminantfree atmosphere, thatprovides good resistance to shock, vibration and acceleration, and thatis adjustable to afford precise characteristics of operation.

As to adjustment, the back stop 37 for the armature is first adjusted toprovide proper armature travel, and is locked, as by solder, in adjustedposition. Then, the actuators 40 are adjusted with the armature firstclamped against the pole pieces and then clamped against the back stop.Finally, the return spring screw 38 is adjusted to provide the properoperate and release points currentwise for the coil. After adjustment,the screw 38 is locked position, such as by solder.

The above described embodiment of the invention is a normally releasedrelay operated only upon and during energization of the coil 18. Inaddition to this embodiment, the present invention provides a latchingrelay affording all of the advantages of the described relayconstruction and having the further advantage that it is operated onopposite hands by momentary current pulses of reversed polarity and isretained in the condition to which it was last operated.Constructionally, the latching relay is similar to the relay abovedescribed except for the few differences depicted schematically inFIGURE 8. In particular, as shown, the pole pieces 24a and 26a in thelatching relay are extended inwardly at the aforesaid inclination to theaxis of the core 16a to a position adjacent the transverse or pivot axisof the armature 14a and are then inclined diagonally away from thearmature at substantially an equal but opposite inclination. In otherwords, the terminal part of each pole piece includes an inner portion24a1-1, 26a-1 and an outer portion 240-2, 26a-2 which portions arerelatively inclined and define an obtuse angle therebetween. The degreeof angularity between the two portions is generally the differencebetween 180 degrees and the maximum swing that the armature is to bepermitted. Preferably, the two pole pieces have the same angularity andboth extend inwardly to locate the juncture between said two portionsthereof adjacent the pivot axis of the armature, the portions 24a-1 and26a-1 and the portions 2411-2 and 26a-2 being parallel and disposed toopposite sides of the armature and its pivot axis. The apex of the angleof each pole piece is disposed adjacent the pivot axis of the armatureand the bisector of that angle would intersect the pivot axis of thearmature 14a, the axis of the core 16a and the longitudinal axis of theheader, all at right angles if the armature pivot axis is not offset,and will essentially do so if the armature pivot axis is offset, due tothe small degree of oifset necessary to balance the armature.

The armature 14a is a permanent magnet, having high coercive force. Theopposite ends of the armature comprise the poles of the magnet, asillustrated by the pole indications in FIGURE 8. Assuming the left-handend of the'arrnature is the north pole and the right-hand end of thearmature is the south po'le,-and that the armature is in the positionshown, the relay is operated by supplying current to the coil 18a in adirection to cause the pole piece 240: to be the south pole and the polepiece 26a to be the north pole of the coil. Thereupon, the northpolarity of theiportion 26a-1 of the pole piece 26a repels the northpole of the armature while the south polarity of the portion 24a-2 ofthe pole piece 24a attracts the north pole or" the armature, and thesouth polarity of the portion 24a-1 of the pole piece 24a repels thesouth pole of the armature while the north polarity of the portion 26a-2ofthe pole piece 26a attracts the south pole of the armature. Thus, fourforces are at work simultaneously, two repelling and two attracting,toinsure positive and rapid operation of the armature by virtue simplyof momentary energization of the coil 18a. To return the armature to itsoriginal position, the coil is energized in the opposite sense,whereupon four forces are-again at work to efiect prompt operation ofthe armature. Once moved,the armature will remain in the posi- 10 tionto which it was last moved by virtue of its own magnetic properties.

By virtue of thedescribed construction, the armature is moved from equalbut oppositely inclined end positions through an are at the midpoint ofwhich the armature is parallel to the core and the header, thereby toafford the advantages described hereinbefore.

To effect operation of the relay in the manner described, a number ofcontrol circuits can be employed. For example, the coil may be energizedfrom the same '=s0urce, 0r from sources of equal power and oppositepolarities, in which case the armature does not require a return spring.Simply by way of example, the coil 18a of the relay could suitably beenergized from a battery B via a switch S capable of reversing the howof current from the terminals of the battery thereby to control thepolarity of the field produced by the coil. In this case, the pi otaxisof the armature is offset only laterally of the armature to compensatefor the actuators, as indicated at CG, and is not offset longitudinallyof the armature as there is no return spring. On the other hand, thecontroi circuit might be so devised as to utilize a relatively highpower source for operating the armature in the clockwise direction and arelatively low power source 2 for operatingthe armature in thecounter-clockwise direction, in which case a return spring(counterbalanced in the manner illustrated in FIGURE 7) could well beemployed to assist the lower powered source in performance of itsfunction.

It should be understood, of course, that the angles of the pole piecesas illustrated in FIGURES 4 to 6 and 8 have been exaggerated forpurposes of convenience and clarity of disclosure. Those skilled in theart may readily determine the appropriate angles from the foregoing de-5 scription and upon consideration of the degree of armature traveidesired.

While I have shown and described what I regard to be the preferredembodiments of my invention, it will be appreciated that variouschanges, rearrangements and modifications may be madetherein withoutdeparting from the scope of the invention, as defined by the appendedclaims.

I claim:

1. In a relay structure having a coil core, a headerdisposed in spacedparallel relation to the core, a plurality of movable contacts on saidheader movable in the direction of the axis of said core, an elongatearmature extending in the direction of said core in the space betweensaid header and said core, said armature being mounted for movement in apredetermined are about a transverse j pivot axis disposed generallycentrally thereof and extending in spaced parallel relation to saidheader, actuators extending generally perpendicularly from said armatureto said movable contacts, a first pole piece fixed to one end of saidcore and including a portion extending between said armature and saidcore at one side of said pivot axis, and a second pole piece fixed tothe other end of said core and including a portion parallel to the saidportion of said first pole piece and extending between said armature andsaid header at the opposite side of said pivot axis, the improvementcomprising that the said portions of said pole pieces are inclined awayfrom the axes of said core and said header respectively toward saidarmature at an inclination equal approximately to one-half the arcuatemovement of said armature whereby the armature at the mid-point of itsmovement is substantially parallelto said header and at one extremity ofits arcuate movement is substantially parallel to said portions of saidpole pieces, and that said actuators at the said mid-point of armature 70 movementare engaged with substantially the center line of therespective movable contacts to minimize imposition of twisting forces onsaid contacts.

2. In a relay having a coil core, pole pieces including first portionsextending outwardly in the same direction from opposite ends of the coreand second portions extending toward one another outwardly of one sideof the core, an elongate armature extending generally in the samedirection as said core at the said one side of said core, said armaturebeing pivotally mounted on an axis extending transversely of said coreand located substantially centrally of the armature, the said secondportions of said pole pieces being opposed respectively to the surfacesof said armature facing toward and away from said core, and a leafspring adjacent the latter pole piece for normally biasing the armatureaway from the pole pieces, the improvement comprising that the saidlatter pole piece includes a third portion extending between the saidfirst and second portions thereof and disposed at an inclination to theplane of said spring, and an adjusting screw threaded through said thirdportion of said latter pole piece and engageable with said spring.

3. In a relay structure comprising a stacked arrangement of a coilhaving an axial core, a header disposed in spaced parallel relation tothe core, an armature sandwiched between the header and the core andpivoted for movement in a predetermined are about a transverse axisdisposed generally centrally thereof, a pair of pole pieces fixed toopposite ends of the core and including first portions extending fromthe core toward the header and second portions extending into the spacebetween the header and the core between the core and the armature andbetween the armature and the header respectively, a plurality of pairsof movable contacts mounted on the surface of said header adjacent saidarmature, and pairs of actuators carried by said armature and extendingto and engageable with said pairs of contacts, the improvementcomprising U-shaped straps fixed at the bights thereof to the oppositeends of said header and at the legs thereof to the first portions of therespective pole pieces for constituting the core, the polepieces, thestraps and the header a rigid frame, said second portions of said polepieces being inclined away from said core and said header respectivelytoward said armature at an inclination equal approximately to one-halfthe arcuate movement of said armature whereby the armature at themidpoint of its movement is substantially parallel to said header, aleaf spring on said armature at the end thereof adjacent the pole pieceextending between said armature and said header for normally biasing thearmature to a position inclined oppositely to said second portions ofsaid pole pieces, the last-named pole piece including a third portionbetween said first and second portions thereof inclined inwardly andtoward said header, a screw threaded through said third portion andengageable with said spring at an angle to the plane thereof foreffecting adjustment of said spring, said screw being accessible betweenthe legs of the respective U-shaped strap, the pivot axis of saidarmature being offset longitudinally of the armature in the direction ofsaid spring for counter-balancing said spring and also being oifsetlaterally of the armature in the direction of said actuators forcounter-balancing the actuators, the actuators of each pair extendinginto respective adjacent holes formed in the armature and being securedtherein by a common upset of the material of the armature and the pairof actuators, the actuators at the said midpoint of armature movementengaging with substantially the center line of the respective contacts.

4. In a relay structure including a coil having a core, a pole piecefixed to each end of said core, said pole pieces including portionsextending outwardly in the same direction from said core and portionsextending toward one another outwardly of one side of said coil, saidpole pieces and said core comprising frame means, an elongate l2 erallyin the same direction as said core and said armature to opposite sidesof said armature, the last-named portions of said pole pieces extendingin said direction to substantially the location of the pivot axis ofsaid armature and then extending diagonally away from said pivot axis,said armature comprising a permanent magnet having its magnetic poles atthe opposite ends thereof, and means for at least momentarily energizingsaid coil and for controlling the polarity of its field upon eachenergization thereof, the improvement comprising that the saidlast-named portions of the pole pieces are inclined relative to saidcore and extend toward said pivot axis at an inclination equalapproximately to one-half the arcuate movement of said armature and thatthe said diagonally" extending parts thereof extend away from said pivotaxis at approximately an equal inclination, whereby the armature ismovable substantially equal distances to opposite sides of a positionwherein it is parallel to said core.

5. In a relay structure including a coil having a core, a pole piecefixed to each end of said core, a header fixed to said pole pieces inspaced parallel relation to said core and together with said pole piecesand said core comprising a rigid frame, said pole pieces extendingoutwardly from said core toward said header and extending into the spacebetwen said header and said coil, an elongate armature pivotally mountedon said frame in the space between said header and said coil formovement in a predetermined are about a transverse axis locatedgenerally centrally thereof, said pole pieces being disposedrespectively to opposite sides of said armature, said pole pieces eachincluding relatively inclined portions defining an obtuse angletherebetween, the juncture of the said portions of each pole piece beinglocated adjacent the pivot axis of said armature at the respective sidethereof, the portion of each pole piece to the one side of said juncturethereof being generally parallel to the portion of the other pole pieceto the other side of its said juncture, said armature comprising apermanent magnet having its magneticpoles at the opposite ends thereof,and means for at least momentarily energizing said coil and forcontrolling the polarity of its field upon each energization thereof,the improvement comprising that the apex of the angle defined by eachpole piece is disposed adjacent the pivot axis of said armature with thebisector of the angle disposed perpendicular to said header, whereby thearmature is movable substantially equal distances to opposite sides of ap0;- sition wherein it is parallel to said header. e

6. In a relay having a coil assembly including a core having at least afirst and a second pole piece fixed to the ends of the core, a headerdisposed in spaced parallel relation to the core, a plurality of movablecontacts mounted on said header for movement longitudinally thereof, anelongate armature mounted between said core and said header for arcuatemovement about its transverse pivotal axis which extends parallel tosaid header and transversely thereof, and actuators carried by saidarmature extending from one side of said armature substantiallyperpendicular to said armature and said movable contacts, theimprovement comprising that portions of said pole pieces are disposedbetween said header and said core, and inclined away from the axis ofsaid core and said header respectively toward said armature at aninclination equal approximately to one half the armate movement of saidarmature, whereby the armature at the midpoint of its movement issubstantially parallel to said header and at one extreme of its arcuatemovement substantially parallel to said portions of said pole pieces,and said pivot axis is offset laterally from the center of the armaturein the direction of said actuators for counterbalancing said actuators.

7. A relay structure as set forth in claim 6 which includes a returnspring carried by one end of said armature for normally actuatingcertainof said contact means and in which the pivot center of the armature isoffset longitudinally of thearm-ature in the direction of the spring forcounterbalancing said spring.

References Cited in the file of this patent UNITED STATES PATENTSBossart Nov. 8, 1932 Edwards et a1 Nov. 30, 1948 Boggenstein Feb. 12,1952 Lewus Mar. 4, 1952

